title: Differential pattern of semantic memory organization between bipolar I and II disorders.
abstract: Semantic cognition is one of the key factors in psychosocial functioning. The aim of this study was to explore the differences in pattern of semantic memory organization between euthymic patients with bipolar I and II disorders using the category fluency task. Study participants included 23 euthymic subjects with bipolar I disorder, 23 matched euthymic subjects with bipolar II disorder and 23 matched control subjects. All participants were assessed for verbal learning, recall, learning strategies, and fluency. The combined methods of hierarchical clustering and multidimensional scaling were used to compare the pattern of semantic memory organization among the three groups. Quantitative measures of verbal learning, recall, learning strategies, and fluency did not differ between the three groups. A two-cluster structure of semantic memory organization was identified for the three groups. Semantic structure was more disorganized in the bipolar I disorder group compared to the bipolar II disorder. In addition, patients with bipolar II disorder used less elaborate strategies of semantic memory organization than those of controls. Compared to healthy controls, strategies for categorization in semantic memory appear to be less knowledge-based in patients with bipolar disorders. A differential pattern of semantic memory organization between bipolar I and II disorders indicates a higher risk of cognitive abnormalities in patients with bipolar I disorder compared to patients with bipolar II disorder. Exploring qualitative nature of neuropsychological domains may provide an explanatory insight into the characteristic behaviors of patients with bipolar disorders.
authors.affiliation: Bipolar Disorder Translational Research Center & Department of Neuropsychiatry, Seoul National University Bundang Hospital, 166 Gumi-Ro, Bundang-Gu, Seongnam, Gyeonggi 463-707, Republic of Korea.
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Chang
authors.forename: Sungwon
authors.initials: S
authors.lastname: Choi
authors.forename: Kyooseob
authors.initials: K
authors.lastname: Ha
authors.forename: Tae Hyon
authors.initials: TH
authors.lastname: Ha
authors.forename: Hyun Sang
authors.initials: HS
authors.lastname: Cho
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Choi
authors.forename: Boseok
authors.initials: B
authors.lastname: Cha
authors.forename: Eunsoo
authors.initials: E
authors.lastname: Moon
mesh_terms: D000328:Adult; D018692:Antimanic Agents / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000523:psychology*; D016000:Cluster Analysis; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D009483:Neuropsychological Tests; D012660:Semantics; D014706:Verbal Learning / Q000502:physiology
chemical_list: D018692:Antimanic Agents; D014150:Antipsychotic Agents